[tex]\it a)\ \ -7,4+4,3=-3,1\\ \\ \\ b)\ \ 3\dfrac{2}{6}-2\dfrac{1}{8}=\dfrac{^{4)}20}{\ 6}-\dfrac{^{3)}17}{\ 8}=\dfrac{80-51}{24}=\dfrac{29}{24}=1\dfrac{5}{24}\\ \\ \\ c)\ \ -4\dfrac{2}{3}:\dfrac{5}{18}=-\dfrac{14}{\not3}\cdot\dfrac{\not18\ ^6}{5}=-\dfrac{84}{5}=-16\dfrac{4}{5}[/tex]
